I. Field
The present disclosure relates generally to communication, and more specifically to techniques for sending information during a change in ciphering configuration.
II. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, etc.
A wireless network may use ciphering to protect information sent over the air. The terms “ciphering” and “encryption” are synonymous and are used interchangeably. At the start of a call, information may be sent in the clear until a ciphering configuration is set up. The ciphering configuration may indicate a particular algorithm and/or pertinent parameters (e.g., security keys) to use for ciphering. After setting up the ciphering configuration, a message may be sent to indicate that ciphering will start at a designated activation time. Information may be sent with ciphering after the activation time.
The ciphering configuration may be changed during the call. After completing the change, a message may be sent to indicate that ciphering with the new configuration will start at a designated activation time. Information may be sent using the old ciphering configuration prior to this activation time and using the new ciphering configuration after the activation time.
To ensure that no information is lost due to a change in ciphering configuration, transmission may be suspended from the time a message regarding the new ciphering configuration is sent to the time an acknowledgement is received for the message. This ensures that a receiver entity is aware of the upcoming transmission with the new ciphering configuration. However, a certain delay is associated with sending the acknowledgement, and suspending transmission during this time may adversely impact performance. For example, if time critical information cannot be sent during the suspension period, then the call may be dropped or other deleterious effects may occur.
There is therefore a need in the art for techniques to send information during a change in ciphering configuration.